Arabidopsis WRKY46, WRKY54, and WRKY70 Transcription Factors Are Involved in Brassinosteroid-Regulated Plant Growth and Drought Responses
Arabidopsis WRKY46, WRKY54, and WRKY70 Transcription Factors Are Involved in Brassinosteroid-Regulated Plant Growth and Drought Responses
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拟南芥 WRKY46、WRKY54 和 WRKY70 转录因子参与油菜素类固醇调节的植物生长和干旱反应
DOI：
10.1105/tpc.17.00364
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发表时间：
2017-06-01
期刊：
影响因子：
11.6
通讯作者：
Yin, Yanhai
中科院分区：
文献类型：
--
作者：
Chen, Jiani;Nolan, Trevor M.;Yin, Yanhai
植物类固醇激素油菜素内酯（BRs）在植物生长发育中起着重要作用。BR信号控制BRASSINOSTERIOD insensitive1 - em - suppressor1 /BRASSINAZOLE-RESISTANT1 （BES1/BZR1）家族转录因子的活性。除了促进生长的作用外，BRs还与植物对干旱胁迫的反应有关。然而，BRs调控干旱响应的分子机制才刚刚开始被揭示。WRKY转录因子在br调控的植物生长中的功能尚未确定，尽管它们在胁迫反应中的作用已被充分记录。本研究发现，拟南芥III类WRKY转录因子WRKY46、WRKY54和WRKY70参与了br调控的植物生长和干旱响应，因为WRKY46、WRKY54和WRKY70三突变体在br调控的植物生长中存在缺陷，对干旱胁迫的耐受性更强。rna测序分析揭示了WRKY46、WRKY54和WRKY70在促进br介导的基因表达和抑制干旱应答基因中的全局作用。WRKY54直接与BES1相互作用，协同调控靶基因的表达。此外，WRKY54被gsk3样激酶BR- insensitive2 （BR通路中的负调节因子）磷酸化并破坏稳定。因此，我们的研究结果表明WRKY46/54/70是重要的信号成分，它积极参与br调控的生长，消极参与干旱响应。
Plant steroid hormones, brassinosteroids (BRs), play important roles in growth and development. BR signaling controls the activities of BRASSINOSTERIOD INSENSITIVE1-EMS-SUPPRESSOR1/BRASSINAZOLE-RESISTANT1 (BES1/BZR1) family transcription factors. Besides the role in promoting growth, BRs are also implicated in plant responses to drought stress. However, the molecular mechanisms by which BRs regulate drought response have just begun to be revealed. The functions of WRKY transcription factors in BR-regulated plant growth have not been established, although their roles in stress responses are well documented. Here, we found that three Arabidopsis thaliana group III WRKY transcription factors, WRKY46, WRKY54, and WRKY70, are involved in both BR-regulated plant growth and drought response as the wrky46 wrky54 wrky70 triple mutant has defects in BR-regulated growth and is more tolerant to drought stress. RNA-sequencing analysis revealed global roles of WRKY46, WRKY54, and WRKY70 in promoting BR-mediated gene expression and inhibiting drought responsive genes. WRKY54 directly interacts with BES1 to cooperatively regulate the expression of target genes. In addition, WRKY54 is phosphorylated and destabilized by GSK3-like kinase BR-INSENSITIVE2, a negative regulator in the BR pathway. Our results therefore establish WRKY46/54/70 as important signaling components that are positively involved in BR-regulated growth and negatively involved in drought responses.